Major breakthroughs are possible in neuroscience, cancer, AIDS and Parkinson's—if Congress learns to set priorities.

If the early years of the 21st century often feel like a retread of the 1970s—economic anxiety, turmoil overseas, American leaders who don't seem to understand what the problems are much less how to fix them—the geneticist Francis Collins suggests less dispiriting resemblances. The "arrow of progress that we're riding in biomedicine" took flight 40 or so years ago but is traveling faster and further now.